Quick change hitch ball assembly

ABSTRACT

A hitch ball assembly includes a towing ball having a mounting aperture and an annular race in communication with the mounting aperture. A post includes a base, an axial bore and a plurality of openings in communication with the axial bore. A ball bearing is received in each of these openings. A plunger is axially displaceable in the post between a first position allowing the towing ball to be removed from or attached to the post and a second position for securing the towing ball to the post while allowing the towing ball to turn on the post. A spring, received in the axial bore, engages an end of the plunger and biases the plunger to the first position.

[0001] This application is a continuation of U.S. application Ser. No.10/113,443 entitled “Interchangeable Hitch Ball having Plunger withJ-Shaped Channel” now U.S. Pat. No. ______, which is incorporated hereinby reference.

TECHNICAL FIELD

[0002] The present invention relates generally to the towing field and,more particularly, to a spring-loaded interchangeable hitch ballassembly which allows an operator to quickly and conveniently changefrom one size towing ball to another in order to meet the needs of anyparticular application.

BACKGROUND OF THE INVENTION

[0003] The use of a ball joint coupling comprising a towing ball andcooperating socket assembly in order to tow a trailer behind a towingvehicle is well known in the art. Such an arrangement provides thenecessary freedom of movement to allow a trailer to track smoothlybehind the towing vehicle while also providing a dependable connection.

[0004] Over the years, towing balls of various diameters have been usedfor this purpose and several industry standard sizes (e.g. 1⅞ inch, 2inch, 2¼ inch and 2{fraction (5/16)} inch in diameter) are now infrequent use. As a result, it is not uncommon for a single towingvehicle to be used to tow various trailers where those trailers areequipped with socket assemblies adapted for operative connection withtowing balls of different diameters. Thus, a need is identified for ahitch ball assembly allowing easy and convenient interchange of towingballs of different diameters so that the hitch of the towing vehicle maybe tailored to fit the socket assembly of the trailer to be towed andthereby meet application needs.

[0005] Toward this end, a number of approaches have been proposed in thepast. Representative of the interchangeable hitch ball art are U.S. Pat.Nos. 4,433,854 to Smith, 5,419,576 to Van Vleet, 5,116,072 to Swensonand 4,522,421 to Vance.

[0006] The Smith '854 patent discloses a post for a towing ballincorporating a spring-biased latch pin for releasably attaching thetowing ball to the base. The Van Vleet '576 patent discloses a post andtowing ball secured together by means of a fastening pin. While theapproaches disclosed in these patents provide secure connection of thetowing ball to the post, the latch pins prevent rotation of the towingball relative to the post. Such rotation is desirable as it minimizesbinding forces and promotes articulation and smooth trailer tracking atboth highway speeds and when maneuvering slowly in confined areas.

[0007] The Swenson '072 patent discloses an interchangeable hitch ballassembly including a post having an annular groove. The towing ball issecured to the post by means of an offset pin which extends tangentiallythrough the annular groove so as to allow relative rotation of thetowing ball on the post. There, however, is some difficulty ineffectively securing the pin in position and the structure proposed inthe Swenson patent for this purpose is relatively expensive to produce.

[0008] The Vance '421 patent discloses an interchangeable trailer ballassembly incorporating a mounting post including a threaded stem, abase, an axial bore and a pair of laterally extending bores. A taperedplunger is received in the axial bore. The plunger is biased by means ofa spring into a position wherein ball bearings are forced outwardly intoengagement with an annular groove or race in the towing ball therebylocking the towing ball in position on the post. An actuator rod may beextended into the axial bore to engage and lift the plunger so as torelease the ball bearings from the groove or race and allow removal ofthe towing ball. While effective, significant user inconvenience mayresult as the user may need to stoop or lay on the ground in order tofish the actuator rod up through the axial bore which opens toward theground. This can be a particularly disturbing problem if the ground iswet and/or muddy.

[0009] A need is therefore identified for an improved interchangeablehitch ball assembly.

SUMMARY OF THE INVENTION

[0010] The advantages and novel features of the invention will be setforth in part in the description that follows and in part will becomeapparent to those skilled in the art upon examination of the followingor may be learned with the practice of the invention. The advantages ofthe invention may be realized and obtained by means of theinstrumentalities and combinations particularly pointed out in theappended claims.

[0011] In accordance with the purpose of the present invention asdescribed herein, an improved hitch ball assembly is provided. The hitchball assembly may be broadly defined as including a post and a towingball carried on the post. At least one displaceable locking element isalso carried on the post in either (a) a first position free of securingengagement with the towing ball or (b) a second position in securingengagement with the towing ball. Further, the assembly includes aplunger carried on the post. The plunger includes at least one channelfor engaging and receiving the at least one displaceable element.

[0012] Still more specifically defining the invention, the hitch ballassembly may include a towing ball having a mounting aperture and anannular race in communication with the mounting aperture. The assemblyalso includes a post having a base, an axial bore and at least oneopening in communication with the axial bore. In a typical arrangement,two opposed openings are provided.

[0013] The hitch ball assembly further includes a ball bearing receivedin each of the openings. Further, a plunger is provided including atleast one J-shaped channel. The plunger is carried in the axial bore ofthe post. Additionally, the hitch ball assembly includes a springreceived in the axial bore and engaging an end of the plunger. Thespring functions to bias the plunger into a first position.

[0014] More specifically describing the invention, the plunger includesa J-shaped channel for receiving each ball bearing. Each J-shapedchannel includes a cavity at a first end. When the plunger is biased bythe spring into the first position, the ball bearings are aligned withand received in the cavities. In this position the ball bearings arereceived more fully within the post and therefore are free of securingengagement with the towing ball. Thus, the towing ball may be removedfrom or installed on the post in this position of the plunger.

[0015] In accordance with additional and more specific aspects of thepresent invention, the post further includes a threaded mounting stemdepending from the base. It is this mounting stem that allows the postto be secured to a hitch bar, tow bar, ball mount head or the like.Additionally, the post is tapered to aid in the securing and removing ofthe hitch ball on the post.

[0016] Still further, the towing ball includes a circular opening incommunication with the mounting aperture and the plunger includes aslotted head. With the hitch ball mounted on the post, the slotted headextends through the circular opening so as to be engageable by a toolwhich may be manipulated to rotate and thereby displace the plungerbetween the first position, allowing installation or removal of thetowing ball, and a second position wherein the plunger forces the ballbearings to project further from the post and engage the annular race inthe towing ball. This functions to secure the towing ball to the postwhile allowing the towing ball to rotate freely on the post. It shouldalso be appreciated that the edges of the post defining the openingsaround the ball bearings are staked so as to prevent the ball bearingsfrom falling out of the post when the towing ball is removed.

[0017] Still other features of the present invention will becomeapparent to those skilled in this art from the following descriptionwherein there is shown and described a preferred embodiment of thisinvention, simply by way of illustration of one of the modes best suitedto carry out the invention. As it will be realized, the invention iscapable of other different embodiments and its several details arecapable of modification in various, obvious aspects all withoutdeparting from the invention. Accordingly, the drawings and descriptionswill be regarded as illustrative in nature and not as restrictive.

BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings incorporated in and forming a part ofthe specification, illustrate several aspects of the present inventionand together with the description serve to explain the principles of theinvention. In the drawings:

[0019]FIG. 1 is a partially exploded, perspective view of the presentinvention;

[0020]FIG. 2 is a detailed cross sectional partially exploded viewshowing the present invention in the first operative position with thetowing ball removed from the post and the ball bearings received in thecavities of the plunger;

[0021]FIG. 3 is a detailed cross sectional view showing the presentinvention in the second operative position with the towing ball securelyheld on the post by engagement of the ball bearings held in the postprojecting into the annular race in the towing ball; and

[0022]FIG. 4 is a detailed perspective view of the plunger, clearlyillustrating one of the J-shaped channels.

[0023] Reference will now be made in detail to the present preferredembodiment of the invention, an example of which is illustrated in theaccompanying drawings.

DETAILED DESCRIPTION OF THE INVENTION

[0024] Reference is now made to FIGS. 1-4 showing the hitch ballassembly 10 of the present invention. The assembly 10 includes a postgenerally designated by reference numeral 12 and a towing ball 14. Asshown, the post 12 includes a base 16. A threaded stem 18 depends fromthe base. The post 12 is mounted to a hitch bar or draw bar by extendingthe threaded stem 18 through an aperture in the hitch bar so that thebase 16 rests flat on the hitch bar. A cooperating nut 20 and lockwasher 22 are then engaged over the threaded stem 18. The nut 20 istightened to provide a secure connection. Of course, a locknut could beutilized in place of the cooperating nut 20 and lock washer 22.

[0025] As best shown in FIGS. 2 and 3, the post 12 includes a taperedupper portion 24 which has an axial bore 26. A plurality of openings 28extend through the wall of the tapered upper portion 24 and communicatewith the axial bore 26. While two opposed openings 28 are illustrated inFIGS. 2 and 3, it should be appreciated that less or more could beprovided in the same plane radially around the circumference of thetapered upper portion 24. A displaceable locking element such as a ballbearing 30 is provided in each of the openings 28. Preferably, the edges32 of the outer wall of the tapered upper portion 24 defining theopenings 28 are staked so as to retain the ball bearings 30 in theopenings.

[0026] The towing ball 14 includes (a) a mounting aperture 34 tapered tomatch the upper post portion 24; (b) a circular opening 35 extendingthrough the top of the ball in communication with the mounting aperture;and (c) an internal, annular race 36 extending continuously around andin communication with the mounting aperture 34. The annular race 36 issized and shaped to receive the ball bearings in the manner shown inFIG. 3.

[0027] A plunger 38 is held in the axial bore 26. As best shown in FIG.4, the plunger 38 includes one or more J-shaped channels 40 with oneJ-shaped channel being provided for each one of the ball bearings 30. Asshown, each J-shaped channel 40 includes a ball bearing receiving cavity42 at a first end thereof. The plunger 38 also includes a slotted head48. As illustrated, the ball bearing receiving cavity 42 is at the endof the plunger 38 opposite the slotted head 48.

[0028] As best illustrated in FIGS. 2 and 3, a compression spring 50 ispositioned in the axial bore 26 of the post 12. One end of thecompression spring 50 engages the bottom wall 51 of the axial bore 26while the other end engages the bottom wall 47 of the plunger 38. As aconsequence, the compression spring 50 functions to bias the plunger 38into a first position shown in FIG. 2. In that first position, the ballbearing receiving cavities 42 at the ends of the J-shaped channels 40 inthe plunger 38 are aligned with and receive the ball bearings 30. Theball bearing receiving cavities 42 are of sufficient depth to receivethe greater portion of the ball bearings 30. As a consequence, the ballbearings 30 have sufficient clearance to retract fully within the outersidewall margin of the tapered upper portion 24 of the post 12. In thisretracted position the ball bearings 30 do not interfere with theinstallation or removal of a towing ball 14 on the post 12. Of course,the tapering of the upper post portion 24 aids in the free removal andseating of the towing ball 14 on the post 12 when changing towing balls.

[0029] When the towing ball 14 is fully seated on the post 12 as shownin FIG. 3, the plunger 38 extends through the opening 35 and an annularshoulder 44 at the end of the mounting aperture 34 engages the upperedge 46 of the post 12. In the seated position, the annular race 36 inthe towing ball 14 is aligned in the same plane with the openings 28 andball bearings 30. In this position, the plunger 38 may be manipulated tosecure the towing ball 14 in position. More specifically, a screwdriveror other tool may be used to engage the slotted head 48 of the plunger38. The plunger 38 is then depressed downwardly into the axial bore 26of the post 12 against the biasing force of the compression spring 50.As the plunger 38 is depressed, the ball bearings 30 are forced from theball bearing receiving cavities 42 into the first leg 52 of eachJ-shaped channel 40 in the plunger 38. Each of the first legs 52 is ofshallower depth than the ball bearing receiving cavities 42 and,accordingly, the plunger 38 effectively forces the ball bearings 30 toproject outwardly through the openings 28 beyond the sidewall of thetapered upper post portion 24. As a result, a portion of the ballbearings 30 are received in the annular race 36 which extendscontinuously around the inner wall of the towing ball 14.

[0030] Once the plunger 38 has been depressed sufficiently to bring theball bearings into the bend 54 of each of the J-shaped channels 40, theplunger is rotated slightly in a clockwise direction. In this manner theball bearings 30 move through the bend 54 into the second leg 56 of theJ-shaped channels 40. The plunger 38 is then released and thecompression spring 50 biases the plunger so that the ball bearings 30each rest at the bottom 57 of the second leg 56 as best shown in detailin FIG. 3. The intermediate wall 60 between the first and second legs52,56 around which the bend 54 is formed functions to hold the ballbearings 30 in the second leg 56 and prevents their free movement intothe first leg 52 leading to the ball bearing receiving cavities 42.Thus, in this second position shown in FIG. 3, it should be appreciatedthat the towing ball 14 is securely held on the post 12 by theengagement of the projecting ball bearings 30 in the annular race 36 ofthe towing ball.

[0031] Simultaneously, the ball bearings 30 are able to move freelythrough the annular race 36 and as a result, this structure allowsrelative rotation of the towing ball 14 on the post 12. This rotationhelps ensure binding free towing and smooth trailer tracking undersubstantially any foreseeable operating conditions. This relativerotation prevents the ball 14 from freezing in place and reduces thewear on the ball and the trailer socket assembly.

[0032] If the operator needs to change the towing ball 14 for anyreason, this maybe conveniently and easily accomplished in a quick andefficient manner. First, the plunger 38 is depressed slightly so thatthe ball bearings 30 are brought into the upper portion of the secondleg 56 of the J-shaped channel 40 which communicates with the bend 54.The plunger 38 is then rotated slightly counterclockwise by engagementof an appropriate tool in the slotted head 48. This causes the ballbearings 30 to move through the bend 54 over the intermediate wall 60,bringing them into alignment with the upper portion of the first leg 52of the J-shaped channel 40. It should be appreciated that the V-shape ofthe wall 61 of the channel 40 opposite the wall 60 prevents the ballfrom hanging up in any way along the top of the wall 60. The plunger 38is then released and the compression spring 50 biases the plungerupwardly giving a clear visual indication of the unlocked condition ofthe plunger.

[0033] As the plunger 38 rises upwardly from the post 12 out of theaxial bore 26, the ball bearings 30 pass along the first leg 52 and arethen received in the ball bearing receiving cavities 42. As noted above,these ball bearing receiving cavities 42 are of sufficient depth toreceive the greater portion of the ball bearings 30. In this position,as the towing ball 14 is lifted from the post 12, the ball bearings 30retract within the openings 28 in the upper post portion 24 until theball bearings are free of the annular race 36. The towing ball 14 maythen be easily removed from the post 12. The operator then selects a newtowing ball 14 for installation on the post 12 and that installation iscompleted in the manner already described.

[0034] The foregoing description of a preferred embodiment of theinvention has been presented for purposes of illustration anddescription. It is not intended to be exhaustive or to limit theinvention to the precise form disclosed. Obvious modifications orvariations are possible in light of the above teachings. The embodimentwas chosen and described to provide the best illustration of theprinciples of the invention and its practical application to therebyenable one of ordinary skill in the art to utilize the invention invarious embodiments and with various modifications as are suited to theparticular use contemplated. All such modifications and variations arewithin the scope of the invention as determined by the appended claimswhen interpreted in accordance with the breadth to which they arefairly, legally and equitably entitled.

1. A hitch ball assembly, comprising: a post; a towing ball carried onsaid post and having a top opening; at least one locking element carriedon said post and displaceable between a first position free of securingengagement with said towing ball and a second position securing thetowing ball to the post; and a plunger carried on said post andextending at least partially through the opening in the towing ball,said plunger including at least one channel for receiving thedisplaceable locking element in the second position.
 2. The assembly ofclaim 1, wherein the channel includes a cavity for receiving thedisplaceable locking element in the first position.
 3. The assembly ofclaim 2, wherein the channel is J-shaped.
 4. The assembly of claim 3,wherein the cavity is at one end of the J-shaped channel.
 5. Theassembly of claim 1, wherein the channel receives the displaceablelocking element in both the first and second positions.
 6. The assemblyof claim 1, wherein said at least one displaceable element is a ballbearing.
 7. The assembly of claim 1, further including a biaser carriedon the post and engaging an end of the plunger.
 8. The assembly of claim1, further including a spring carried on the post and engaging an end ofthe plunger.
 9. The assembly of claim 1, wherein the plunger includes aslotted head extending through the opening and engageable by a tool inorder to rotate and thereby move the plunger to displace the lockingelement between the first and second positions.
 10. The assembly ofclaim 1, wherein the post is tapered.
 11. A hitch ball assembly,comprising: a post; a towing ball carried on the post; at least onelocking element carried on the post and displaceable between a firstposition free of securing engagement with the towing ball and a secondposition securing the towing ball to the post; a plunger carried on thepost, the plunger including at least one cavity for receiving the atleast one displaceable element; a biaser carried on the post andengaging an end of the plunger, the biaser being relaxed when thelocking element is in the first position.
 12. The assembly of claim 11,wherein the biaser is a compression spring.
 13. The assembly of claim11, wherein the cavity is part of a channel.
 14. The assembly of claim13, wherein the channel is J-shaped.
 15. The assembly of claim 13,wherein the channel receives the at least one displaceable lockingelement in both the first and second positions.
 16. The assembly ofclaim 11, wherein the plunger includes a slotted head extending throughthe opening and engageable by a tool in order to rotate and thereby movethe plunger to displace the locking element between the first and secondpositions.
 17. The assembly of claim 1 1, wherein the post is tapered.18. A hitch ball assembly, comprising: a post; a towing ball carried onthe post and having an opening; at least one locking element carried onthe post and displaceable between a first position free of securingengagement with the towing ball and a second position securing thetowing ball to the post; a plunger carried on the post and extending atleast partially through the opening in the towing ball, the plungerreceiving the at least one displaceable element in both the first andsecond positions; and a biaser carried on the post and engaging an endof the plunger, the biaser being compressed by the plunger when thelocking element is in the second position.
 19. The assembly of claim 18,wherein the biaser is a compression spring.
 20. The assembly of claim18, wherein the plunger includes a slotted head extending through theopening in the towing ball and engageable by a tool in order to rotateand thereby move the plunger to displace the locking element between thefirst and second positions.